Cup of tea, and a big breakfast normally does it for me.
In an emergency - vomiting.
The worst hangover I had was when I shared two litre bottles of vodka with two other friends, along with cider, malibu and other bits and bobs. I stumbled to the toilet in the morning thinking I was going to be sick but I wasn't (I've never been sick from alcohol :s) and fell asleep in the bathroom.... ;p